Question - Using the * button for focusing??

[garethhhhh]

I've heard from some 1D users that they use the * button to focus while in AI Servo Mode, this allows them to recompose and take the picture.

I would be very interested to know if this can be done with the 10D?


Thanks in advance,

Gareth

[EoSD30fReAk]

It should be possible.
i believe it's Custom function nr 4

[GenEOS]

Back button focusing takes a little while to get used to, but it will make your action shooting a lot easier and increase the speed at which you can obtain focus and keep it. By separating these two functions, you can train your mind to fix the focusing with the thumb and fire with your finger. I like it and use it all the time for action shooting.

[petiot]

i use it on the 10D so yes it is possible!! :)

however it takes a while to get used to. at the beginning i was focusing and moving on the subject so sometime you end up a bit out of focus, also for fast action this difficulty is accentuated, since the thumb - finger pressing sequence can not be as fast as the half press/full press action on the shutter

[garethhhhh]

Thanks for the advice everyone! 8)

[Cordell]

I've heard/read about others using the "*" to focus as well. However, I can't imagine what difference it would actually make over using the shutter button. I also don't shoot action shots or use the AI Servo mode either.

Can someone give an example of why it would matter? Sure I can test it myself, but climbing the learning curb "could" be something that proves to be useless "for me".

Please help. I seek knowledge.

Cordell

[Tapeman]

Another advantage of custom function 4 is you can focus and then when when you are ready to shoot you press the shutter realease and the camera does not change the focus it just sets exposure. (if you are in an AE mode)

I use it all the time.

[MediaMagic]

I use the * for focus most of the time. One advantage, as Tapeman indicates, is that you can prefocus for a specific distance/area (in any direction) and then just fire the shutter at will without the camera messing up the focus you've set. Kinda like an automated manual focus.

[GenEOS]

If you are not shooting action, it is probably not all that usefull. It is an exposure lock of sorts. It keeps the camera from hunting for focus, which happens to me and my D60 a lot in lower lighting.

It does take time to get used to. But you will, and you will like it. I have found it increases the percentage of sharp images in an action sequence.

[Ferdinand]

So if I set CF4 to 3 I hit the * to AF lock and then shuttle to shoot and the AE will be done just before capturing the image correct?

Now if I am in AI Servo, and fix my focus on lets say a baseball player, and if he starts running, will AI Servo take over and track the player instead?

Regards,
Ferdinand

[yenoram]

AI Servo will only take over if you continue to hold the * button down. If you simply focus on the player using the * button and release you are effectively in manual focus mode. As others have said, it takes some getting used to, however, once you do you'll like particularly for sports and action type shots.

[Ferdinand]

Thanks for the response, so if after I lock focus but want to lock exposure before recompose does that mean I would have to go back to CF4 and change it back to 0?

Regards,
Ferdinand

[petiot]

Quote"I've heard/read about others using the "*" to focus as well. However, I can't imagine what difference it would actually make over using the shutter button. I also don't shoot action shots or use the AI Servo mode either.

Can someone give an example of why it would matter? Sure I can test it myself, but climbing the learning curb "could" be something that proves to be useless "for me". End Quote

ian example: if you are taking a succession of several shots, not in a sequence (means you keep the shutter pressed) but one by one fairly rapidly. e.g. you are in a footbal match and you follow the action taking soht and trying to catch a particular moment (rather than firing 3 frame pers second for 10 sec hopping that maybe you ll get right moment). In this case if you have the autofocus on *, you need to quickly press * and then the shutter. this can be trickier than simply going through the sequence (shutter half pressesd fully pressed". which is why i beleive camera shutter have been designed this way.

obviously if you use Ai servo this problem is moot.

Quote"Thanks for the response, so if after I lock focus but want to lock exposure before recompose does that mean I would have to go back to CF4 and change it back to 0?" End Quote

no, the exposure is locked by half pressing the shutter. So you can lock the exposure, recompose, lock the focus(* button) and fully pressed.

Dan

[Ferdinand]

Ah thanks Dan, drats I could for the world figure out why it wasn't locking the exposure I want. So now half press shuttle is lock AE instead of lock AF as in option CF4-0? Thanks again.

Regards,
Ferdinand

[slejhamer]

Ah thanks Dan, drats I could for the world figure out why it wasn't locking the exposure I want. So now half press shuttle is lock AE instead of lock AF as in option CF4-0? Thanks again.

Regards,
Ferdinand

To clarify:

There is no AE lock with C.Fn-04-3. If you want it, use C.Fn-04-1 which locks exposure when the shutter is pressed halfway. With 04-3, exposure is set when the shutter is fully depressed (shot taken.) That is the only difference between the two.

Also, if you want to retain FEL while using 04-1 or 04-3, you must also set C.Fn-13 to 4 (assign FEL to the assist button.)

Finally, with the default setting of C.Fn-04-0, the half-pressed shutter only locks AE when you are in one-shot mode with evaluative metering. In AI servo (one shot or continuous firing) exposure is not set until the shot is taken. Apart from using the * to hold focus tracking, this is exactly the same as C.Fn-04-3.

Cheers,

[Ferdinand]

Thanks for the clarification.

Regards,
Ferdinand